Abstract. Yanti Y, Astuti FF, Habazar T, Nasution CR. 2017. Screening of rhizobacteria from rhizosphere of healthy chili to control bacterial wilt disease and to promote growth and yield of chili. Biodiversitas 18: 1-9. Bacterial wilt on chili cause by Ralstonia solanacearum. This disease is important, causing plant death and significant yield losses. Biological control is desirable because control with other methods gives variable results. One of the important group of biological agent is the plant growth promoting rhizobacteria (PGPR). This group can control plant pathogens and enhance the growth and yield through direct and indirect mechanisms. The aim of this research was to obtain indigenous rhizobacterial isolates from rhizosphere of healthy chili, which are effective to control bacterial wilt disease and to promote plant growth as well as to increase plant yields. The rhizobacterial isolates were collected from healthy chili rhizosphere in endemic area of bacterial wilt at Banuhampu Sub-district, Agam District, West Sumatra, Indonesia. Screening method of rhizobacterial isolates to control bacterial wilt was based on in planta technique. This technique was consist of three steps, as follow: (i) Screening of 43 rhizobacterial isolates to induce the hypersensitive reaction on Mirabilis jalapa. (ii) Screening of 42 rhizobacterial isolates (from first step) to increase growth of chili seedlings and (iii) Screening of 20 selected rhizobacterial isolates (from second step) to control bacterial wilt on chili. R. solanacearum were inoculated on the 6 weeks chili plants using Two strains of rhizobacterial isolates from chili rhizosphere (RZ.2.1.AG1 and RZ.1.3.AP1) showed high potential for disease suppression and also increased growth and yield of chili.

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Abstract. Yanti Y, Hamid H, Reflin, Warnita, Habazar T. 2019. The ability of indigenous Bacillus spp. consortia to control the anthracnose disease (Colletrotricum capsici) and increase the growth of chili. Biodiversitas 21: 179-186. Anthracnose disease caused by Colletotrichum capsici can reduce yields of chili up to 80%. The control of anthracnose disease is generally carried out using synthetic fungicides. However, the use of these fungicides can pollute the environment and harm human health. One alternative control that needs to be developed is the use of Bacillus spp. as a biocontrol agent. The study was conducted to obtain an indigenous Bacillus spp. consortium that compatible as a biological agent for the control of the anthracnose diseases and promoting the growth of chili plants. The experiment was arranged as a completely randomized design, consisted of three stages, namely: 1) inhibitory test of indigenous Bacillus spp. against C. capsici in vitro, 2) compatibility test of indigenous Bacillus spp. and 3) Test of indigenous Bacillus spp.consortium for controlling C. capsici and promoting the growth of chili. The results showed that eight species of indigenous endophytic bacteria could inhibit the growth of C. capsici in vitro. All combinations of indigenous Bacillus spp. were compatible for controlling C. capsici. Four combinations of Bacillus spp. were able to increase the growth of chili plants. K1 consortium (Bacillus pseudomycoides strain SLBE 3.1 AP, Bacillus thuringiensis strain SLBE 2.3 BB, Bacillus toyonensis strain AGBE 2.1 TL) was the best consortium for controlling C. capsici.

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Blood diseases caused by Ralstonia solancearum Phylotype IV is a major cause of production loss of banana in Indonesia, particularly for areas in West Sumatera. Currently there is a lack of information on blood diseases. The objective of this study was to obtain data of insect diversity and its potential as a dissemination agent of R. solanacearum Phylotype IV in West Sumatera. This research was conducted with a purposive sampling method in the Tabek Panjang highlands, District of Baso, Agam Regency and Pasar Usang lowland, district of Batang Anai, Pariaman Regency, West Sumatera. The results showed that banana plants infected by R. solanacearum Phylotype IV have a high diversity of flower-visiting insects. The diversity of insects in the lowlands is higher than that in highland and mainly are dominated by Trigona spp. (Hymenoptera: Apidae), Drosophila sp. (Diptera: Drosophilidae). To test the potential of both insect as vector of the blood diseases, isolated and identification of the bacteria using triphenyl tetrazolium medium chlorid (TTC) was used. Result showed that bacteria isolated from both insect are R. solanacearum hence providing evidence of the insect as vector of the blood diseases. Both insects have the potential to be vector of R. solanacearum Phylotype IV in West Sumatera. The identification of the bacteria that causes the disease. The identification of bacteria that is spread by flower visitors insects are R.solanacearum Phylotipe IV.